1. Field of the Invention
This invention relates data processing for geophysical exploration, more specifically related to using slant-stack for time gather to angle gather conversion.
2. Description of the Related Art
For background information regarding conversion from time gather to angle gather, one may refer to a paper by Sava and Fomel (2006), “Time-shift imaging condition in seismic migration” published in Geophysics, Vol 71, Issue 6. They proposed time shifted imaging conditions and also the equations to convert time shift gathers to angle gathers. We observe limitations of the proposed equation and suggest an alternative to overcome the shortcoming.
Conversion of time gathers to angle gathers involves an intermediate step of slant-stacking Sava and Fomel (2006) proposed the slant-stack to be carried out along Z-axis followed by the dip correction. However, we believe that the results of time to angle gather conversion using the proposed scheme start being inaccurate for dips with large angles, for example, angles greater than sixty degrees, and the method totally fails for a near vertical reflector (ninety degree dip).
It is desirable to have a method and an apparatus to correct the inaccuracies.